1. Field of the Invention
The invention pertains to the field of nucleic acid detection. More particularly, the invention pertains to a lateral flow assay for detection of nucleic acid targets.
2. Description of Related Art
Lateral flow immunoassays are a subset of antibody-based immunoassays combining various reagents and process steps in one assay strip, thus providing a sensitive and rapid means for the detection of target molecules. Lateral flow immunoassays are available for a wide area of target analytes and can be designed for sandwich or competitive test principles. Generally high molecular weight analytes with several epitopes are analyzed in a sandwich format whereas small molecules representing only one epitope are detected by means of a competitive assay. The first tests were made for human chorionic gonadotropin (hCG). Today, there are commercially available tests for monitoring ovulation, detecting infectious disease organisms, analyzing drugs of abuse, and measuring other analytes important to human physiology. Products have also been introduced for veterinary testing, environmental testing, and product monitoring.
Rapid point-of-care analysis is becoming increasingly important in the diagnosis and treatment of various viral and other pathogenic microbiological agents. Prior art point-of-care tests, such as lateral flow immunochromatography tests, are immunoassays involving an antibody and its antigen. Binding assays in such formats operate on the basis of ligands and receptors and their associated binding constants. The inherent deficiencies in the associations between antibodies and their antigens are well known in the art in that ligand-receptor binding assays are prone to degrade with temperature cycling and heat stress while in storage, and interferences often occur from components in the sample matrix, causing non-specific binding during the assay and leading to false results. These inherent limitations do not provide sufficient specificity in the ligand-receptor interaction for reliable assay results. Ligand-receptor binding provides the above-mentioned specificity and limitations to a protein antigen target but not to a nucleic acid sequence coding for the protein.